1. Field of the Invention
The present invention relates to an apparatus for treating tubular fabrics.
2. Description of the Prior Art
In the treating of a tubular fabric, such as knitted fabric, which are formed in the shape of an elongated tube on a rotary knitting machine, it is customary to wash, dye, scour and calender the fabric while it is still in the form of a tube. After such treatment, the tube is normally split so that it can be cut and sewn into garments.
The handling of such a tubular fabric is relatively difficult since the fabric is knitted with interlocking loops of yarn and is, therefore, easily stretched in the longitudinal or transverse directions, and it is equally easily shrunk. The fabric in a tubular or a web form cannot be gripped firmly in handling since such handling would leave detrimental marks on the fabric.
In the handling of a tubular fabric, a problem of handling is also presented when the fabric contains a considerable amount of moisture after it has been washed, scoured or passed through a resin bath. For instance, if the fabric is carried at a relatively high speed through a pair of press rollers or other surfaces for pressing the fabric to squeeze out the liquid, a balloon has a tendency to form upstream of the pressing surface. This balloon is formed by liquid and air which accumulates within the tubular fabric. Different methods have been tried to remove the liquid from the fabric, such as applying conventional suction boxes instead of the rollers. It has been found, however, that with conventional suction boxes, the amount of negative pressure required to provide sufficient suction across the width of the fabric to prevent the formation of a balloon is excessive and uneconomical, while the drag experienced on the fabric is detrimental since it helps to stretch the fabric longitudinally.
Furthermore, in the type of equipment known in the trade as a quetch, including a floating spreader inside the tubular fabric driven by two edge rollers and a pair of driven squeeze rollers for squeezing the liquid and air out of the fabric downstream of the spreader, it has been found that, at relatively high speed, if there is a snag in the tubular fabric, the spreader is often dislodged from the drive rollers and jams into the nip formed between the driven squeeze rollers, sometimes causing damage not only to the fabric, but to the spreader and the rollers.